Interlock for electrical connectors



March 25, 1952 CARLSEN INTERLOCK FOR ELECTRICAL ,CONNECTORS Filed Aug. 10, 9

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INVE R- Patented Mar. 25, 1952 UNITED STATES earsm f) FFl-C E ENTEKLOCK FOR ELECTRICAL QONNE'JTORS Otto Carlsen, Monrovia, Qalif. ippiieaiien Augustli'i, 1949, Scrial'No. 109,60!

1 Claim. 1

This invention relates to new and useful im provements and structural refinements in electrical connectors, particularly those commonly employed at the end of an attachment cord for receiving an attachment plug at the adjacent end of a connecting cord, the principal object of the invention being to firmly and securely hold the attachment plug so as to prevent undesired separation of the two cords.

This object is achieved by the provision of the instant connector which embodies in its construction means for frictionally engaging and clamping the prongs of an attachment plug, an important feature of the invention, therefore, residing in the structure of the connector and in the clamping means whereby the frictional engagement or gripping of the attachment plug prongs is facilitated.

Some of the advantages of the invention lie in its simplicity of construction, in its dependable operation, and in its adaptability to economical manufacture.

With the above more important objects and features in View and such other objects and features as may become apparent as this. specification proceeds, the invention consists essentially in the arrangement and construction of parts as illustrated in the accompanying drawings, in which:-

Figure 1 is a perspective view of the invention;

Figure 2 is a vertical sectional view thereof;

Figure 3 is a horizontal cross-sectional view, taken substantially in the plane of the line 3-3 in Figure 2; and

Figure .4 is a group perspective view of one of the prong-contacting members and terminals used in the invention.

Like characters of reference are employed to designatev like parts in the specification and throughout the several views.

Referring now to the accompanying drawings in detail, the invention consists of an electrical connector designated generally by the reference character ID, the same embodying in its construction an elongated body l2 comprising a main body member l4 and an extension 16, both of which are preferably formed from insulating material such as rubber, or the like.

The body members l4, l5 are separably connected together by an interlocking flange and groove arrangement 18, it being understood that the extension I6 is sufficiently resilient to permit the interlocking flange and groove to be separated for the purpose of applying the entire connector to an extension cord 26, or for purposes of inspection, or the like.

It is to be also noted that the body extension I6 is hollow, as indicated at 22, while the main body portion 14 is provided with a plurality of slots 24 which communicate with the interior of the extension (6 and are adapted to receive the prongs 53 of a conventional attachment plug (not shown).

A prong-contacting member or strap 26 is rigidly secured in one side wall of each of the slots 21% by being embeddedin the main body portion it at manufacture, and the inner ends of the members 25 are provided in opposite longitudinal edges thereof with transversely aligned notches 28 to accommodate a substantially U-shaped keeper 30 which is secured to the associated contact member by a terminal screw 32.

The actual wires 3 1 of the conductors 20 extend into the hollow interior 22 of the body extension it and are clamped between the members 25 and the keepers 30, whereby undesired separation of the wires from the contact members is effectively prevented.

The essence of novelty of the invention resides in the provision of a plurality of prong-clamping elements or blocks 3% which are slidable inwardly and outwardly in suitable recesses 38 formed in the main body portion it, it being noted that the outer circumferential surface of the body portion [4 is provided with an annular groove or channel 49 from which the recesses 38 extend inwardly and communicate with the slots 24, as is best shown in Figure 2.

The groove 48 is intended to accommodate an expansible and contractible clamp 42 which simply assumes the form of a substantially circular band provided at the ends thereof with a pair of spaced, opposing ears 44, 46, the former car being screw threaded to receive a clamping stud 48, while the latter ear is provided with an aperture through which the stud may freely slide, as will be clearly apparent from Figure 3.

One end of the stud 88 is equipped with an eye 5%), which in turn. is pivotally connected as at 52 to a cam 54 which is operatively engageable with the adjacent portion of the clamp band 42 and is provided with a suitable finger piece 55.

When the invention is placed in use, the prongs of the attachment plug are simply inserted in the slot 24, as indicated by the phantom lines 58 in Figure 2, so that they electrically engage the contact members 255', during which operation the cam 54 is, of course, in an open position as indicated at 60 in Figure 3. In this position the clamp 42 is expanded so as to facilitate insertion of the prongs but after the prongs are inserted the cam 54 is pressed toward the clamp 42 by means of the finger piece 5%, so that the clamping band is contracted and the blocks 36, which are engageable by the clamping band, are pressed inwardly so that the prongs 58, in turn, are frictionally engaged withthe contact members 26. It will be apparent-from the foregoing that in this manner undesired separation of the connecc0 tor and attachment plug will be prevented, but,

needless to say, separation thereof will be readily facilitated by simply opening the cam 54 of the clamp 42.

It is believed that the advantages and use of the invention will be clearly apparent from the foregoing disclosure and, accordingly, further description thereof at this point is deemed unnecessary.

Having described the claimed as new is:

In an electrical connector, the combination of an elongated body provided in one end thereof with a set of longitudinally extending slots having inner and outer opposing walls, a set of flat conductor members provided at the inner walls invention, what is of the respective slots and spaced from the outer walls whereby to receive therebetween the prongs of an attachment plug, the side wall of said body being formed adjacent the slotted end thereof with a perimetric keeper groove and with a set of recesses extending inwardly from said groove to the outer walls of the respective slots, 3. set of prong clamping blocks slidable inwardly and outwardly in said recesses, an expansible and contractible band positioned in said groove in en gagement with outer ends of said blocks, the ends of said band being provided with a pair of spaced out-turned ears, an adjustable fastening element attached to one ear and extending slidably through the second ear, an eye on said element adjacent said second ear, and a cam pivoted to said eye and operatively engaging said band, whereby the latter may be contracted to frictionally engage inner ends of said blocks with prongs inserted in said slots.

OTTO CARLSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,129,491 Housel Feb. 23, 1915 1,517,196 Cuppett Nov. 25, 1924 2,289,172 Beal July '7, 1942 2,494,755 Grover Jan. 1'7, 1950 

